Using

a two-dimensional differential in-gel electrophoresis (DIGE) approach, different samples prelabeled with mass-matched and charge-matched fluorescent cyanine dyes (Cy2, Cy3, and Cy5) can be coseparated in the same two-dimensional gel. An internal standard is used in every gel to negate the problem of intergel variation.20, 21 In this study, a two-dimensional DIGE proteomic approach was employed to compare the proteome of Huh-7 cells overexpressing either miR-17-5p or mock controls to identify clusters of proteins (and pathways) directly or indirectly regulated by miR-17-5p. We identified a cohort of proteins indirectly regulated by miR-17-5p during the stress response, signal transduction, and metabolism. A representative molecule that was differentially phosphorylated, heat shock protein 27, was further confirmed by western

selleck screening library blotting. The specific regulatory mechanisms and the effects of miR-17-5p-induced up-regulation http://www.selleckchem.com/products/byl719.html of phosphorylated heat shock protein 27 in HCC cells were also analyzed. DIGE, differential in-gel electrophoresis; HCC, hepatocellular carcinoma; HSP27, heat shock protein 27; MAPK, mitogen-activated protein kinase; miRNA, microRNA; MMP-2, matrix metalloproteinase 2; siRNA, small interfering RNA. For a description of the patients and methods used in this study, see the Supporting Information. The miR-17-5p up-regulation model was created using Huh-7 cells stably expressing pEZX-17-5p (clone 1 and 2). The miR-17-5p levels of clone 1 and 2 cells, pEZX-MR01-Huh-7 cells, and untreated Huh-7 cells were determined using real-time polymerase chain reaction. We observed significant up-regulation of miR-17-5p in clone 1 and 2 cells compared with mock control or untreated cells (Fig. 1A). To determine whether miR-17-5p

is associated with tumorigenesis or metastasis, clone 1 and pEZX-17-5p-Huh-7 cells were implanted through a subcutaneous route into the flanks of nude mice or orthotopically into the livers of nude mice (Fig. 1D). Up-regulation of miR-17-5p significantly facilitated overall tumor growth as assessed by measurements of tumor volume (Fig. 1B,C). The orthotopic tumor model yielded a similar tumor growth trend as seen in the original injection site. Clone 1 cells showed extensive hepatic invasion with a larger tumor volume than controls (Fig. 1E,F). see more After DIGE, the Cy2, Cy3, and Cy5 channels of each gel were individually imaged, and the images were analyzed using Decyder 5.0 software. On the basis of the average intensity ratios of protein spots, a total 30 protein spots were found to be dynamically changed in clone 1 cells (Fig. 2A), including 18 significantly up-regulated protein spots (ratioclone 1/pEZX-MR01 ≥ 1.3; P ≤ 0.05) and 12 significantly down-regulated protein spots (ratioclone 1/pEZX-MR01 ≤ 0.7; P ≤ 0.05). To identify the differentially expressed proteins in clone 1 cells, 28 protein spots with a threshold greater than 1.